The present invention generally relates to a copying apparatus and more particularly, to a variable magnification copying apparatus of a movable optical system type (i.e., stationary original document platform type).
With respect to the variable magnification copying apparatus of the above described type employing a zoom lens assembly, it has been attempted to further improve the magnification varying functions in order to cope with the recent diversification in the sizes of copy paper sheets to be employed. As a result, it has become possible to copy onto copy paper sheets of any sizes, and simultaneously, to effect copying from original documents of any sizes onto copy paper sheets of regular sizes.
Meanwhile, together with the improvement of the magnification varying functions, there have also been conventionally proposed various measures to prevent miscopying for the promotion of operability. In such proposed measures as referred to above, it is so arranged, for example, to input original document sizes, or to input values for original document sizes as detected by a scale attached to an original document platform.
In the known practice as described above, however, although not many problems are encountered with respect to the original document of a regular size, if the original document is of an irregular size, input of such an irregular original document size imposes a heavy burden on the operator, and the actual state is such that the magnification varying functions are not fully utilized effectively.
As described so far, in the conventional variable magnification copying apparatuses, there have been such disadvantages that they lack in efficient operability especially when original documents of irregular sizes are copied onto copy paper sheets of regular sizes through varied magnifications, thus being capable of producing miscopying or loss of images, etc.